Micromechanical switches are known in the art. The basic structure of a micromechanical switch includes a source contact, a drain contact, and a gate contact. A conductive bridge or beam structure is attached at one end to the source contact. The bridge structure overhangs the gate contact and the drain contact and is capable of coming into mechanical and electrical contact with the drain contact when deflected downward by an electrostatic force developed between the bridge and the gate contact. Once the bridge is in contact with the drain contact, the bridge permits current to flow from the source contact to the drain contact. The voltage on the gate controls the actuation of the device by generating an electrostatic field in the space between the bridge and the gate contact.
Switches of this type are disclosed in U.S. Pat. No. 4,674,180 to Zavracky et al., the whole of which is incorporated by reference herein. In this device, a specific threshold voltage is required to deflect the bridge structure so that it may contact the drain contact. Once the bridge comes into contact with the drain contact, current flow is established between the source and the drain.
The micromechanical devices typically have a length of 60 microns and a bridge tip to drain contact spacing of two microns. These micromechanical devices are either in the "ion" condition wherein electrical communication has been established between the source and the drain, or "off" wherein there is no electrical communication between the source and the drain. It would be desirable to have a micromechanical device which functions as an active micromechanical electronic device which provides a variable output dependent upon the level of an input.